Gemstones have their own unique optical response and this optical response can be used for accurate identification of the gemstones. In this regard, U.S. Pat. No. 3,947,120 discloses an arrangement for providing an optical fingerprint of a gemstone where a laser beam is focused on a gemstone and the optical response of the gemstone is recorded on a recording medium, preferably a photographic medium. This arrangement provides a fingerprint of the gemstone which is reproducible and has been held by the courts to be sufficient evidence to prove that the gemstone under consideration having a certain optical response is the same as a previously identified gemstone having essentially the same optical response.
This prior art structure used a photographic medium and the actual record was sensitive to the exposure period as well as the power of the laser.
European Application No. 0 042 361 discloses a device for producing a reproducible identification pattern of a polished gemstone in which collimated light is directed onto the gemstone and the directions of the refracted and reflected light beams are determined.
Applicant's own PCT application No. PCT/CA91/00424 discloses improvements to systems for recording the optical fingerprint of gemstones.
Applicant's previous systems were largely manual based systems and there is a need for a more automated system that provides a number of new features that both make the gem registration process more reliable and simpler.